Neurobiology I

Neuron

  • 4.1 The Neuron Is the Building Block of the Nervous System – Introduction to Psychology – 1st Canadian Edition

  • Specialized to use changed in membrane potential to communicate signals across land distances

  • Voltage difference across cell

    • measured in V or mV

    • resting membrane potential - -70mv

      • Due to

        • Ions

        • Na/K pump

        • Leaky Channels

  • Membrane potentials

    • Equilibrium potential

      • membrane potential at which the net flow of an ion is zero

      • Use Nernst Equation

        • E = (RT / zF) * ln([ion]outside / [ion]inside)

      • Goldman Equation

        • Compares with all the ions

Drive force governs ion flow

  • The difference between the membrane potential and the ion equilibrium potential

  • larger the difference, the stronger the driving force

Action Potential

  • Depolarization

    • membrane potential becomes less negative

    • positive ions enter and negative ions exit

  • Hyperpolarization

    • membrane potential becomes more negative

    • positive ions exit and negative enter